SNP-based LOH of hepatocellular carcinoma (HCC)
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE36277 | GEO | 2015/02/28
SECONDARY ACCESSION(S): PRJNA153005
REPOSITORIES: GEO
Similar Datasets
Project description:High frequency of loss of heterozygosity (LOH) at locus D4S2964 was found in hepatocellular carcinoma (HCC) by our previous studies and others’. The present study was designed to explore genes around the locus affected by LOH and their clinical implications. 440 SNPs located at 49 genes around D4S2964 were selected from NCBI website for the SNPs microarray fabrication. LOH of these SNPs markers in 112 cases of HCC tissues and paired adjacent liver tissues were investigated by the SNP microarray. A map of LOH of SNPs in genes around D4S2964 was constructed. 112 pairs of HCC tissues and corresponding non-tumor tissues was genotyped. LOH and its clinical implication was analyzed.
2015-02-28 | E-GEOD-36277 | biostudies-arrayexpress
Project description:Structural changes of chromosomes play important roles in the carcinogenesis of colorectal carcinoma (CRC). Here, by using SNP-typing arrays, we have tried to screen for recurrent chromosome copy number changes and loss-of-heterozygosity in the genome of colorectal carcinoma. Genomic DNA was isolated from tumor and paired normal tissues of CRC (n=94), and was hybridized to Affymetrix Mapping 50K Xba 240 arrays. Chromosome copy number and LOH likelihood score was inferred at every SNP locus with CNAG2.0 software (http://www.genome.umin.jp). Keywords: Comparative genomic hybridization
2008-08-21 | GSE11417 | GEO
Project description:Structural changes of chromosomes play important roles in the carcinogenesis of colorectal carcinoma (CRC). Here, by using SNP-typing arrays, we have tried to screen for recurrent chromosome copy number changes and loss-of-heterozygosity in the genome of colorectal carcinoma. Genomic DNA was isolated from tumor and paired normal tissues of CRC (n=94), and was hybridized to Affymetrix Mapping 50K Xba 240 arrays. Chromosome copy number and LOH likelihood score was inferred at every SNP locus with CNAG2.0 software (http://www.genome.umin.jp). Experiment Overall Design: Tumor samples and paired normal tissues (n=94 for each) were hybridized to the microarrays. Signal intensity data as well as genotype data were compared between a pair of tumor and normal samples with CNAG2.0. The resultant copy number and LOH likelihood score for each sample are thus calculated from two datasets (tumor and normal).
2008-10-26 | E-GEOD-11417 | biostudies-arrayexpress
Project description:We have employed a laser capture microdissection technique and single nucleotide polymorphism arrays to characterize genomic alterations associated with the development of glioblastomas. Combined analysis of LOH and copy number revealed that more than half of the identified 254 LOH loci showed no copy number alteration, indicating the presence of copy-number neutral LOH Keywords: DNA copy number, Loss of heterozygosity
2009-03-01 | GSE10922 | GEO
Project description:Screening for gene copy-number alterations (CNAs) has improved by applying genome-wide microarrays, where SNP arrays also allow analysis of loss of heterozygozity (LOH). We here analyzed 10 chronic lymphocytic leukemia (CLL) samples using four different high-resolution platforms: BAC arrays (32K), oligonucleotide arrays (185K, Agilent), and two SNP arrays (250K, Affymetrix and 317K, Illumina). Cross-platform comparison revealed 29 concordantly detected CNAs, including known recurrent alterations, which confirmed that all platforms are powerful tools when screening for large aberrations. However, detection of 32 additional regions present in 2-3 platforms illustrated a discrepancy in detection of small CNAs, which often involved reported copy-number variations. LOH analysis revealed concordance of mainly large regions, but showed numerous, small nonoverlapping regions and LOH escaping detection. Evaluation of baseline variation and copy-number ratio response showed the best performance for the Agilent platform and confirmed the robustness of BAC arrays. Accordingly, these platforms demonstrated a higher degree of platform-specific CNAs. The SNP arrays displayed higher technical variation, although this was compensated by high density of elements. Affymetrix detected a higher degree of CNAs compared to Illumina, while the latter showed a lower noise level and higher detection rate in the LOH analysis. Large-scale studies of genomic aberrations are now feasible, but new tools for LOH analysis are requested.
2008-12-10 | GSE13557 | GEO
Project description:Genome modification in mouse embryonic stem cells (mESCs) has provided the versatile platform to analyzing gene functions in mammalian cells. Bloom helicase-deficient mESCs showed elevated rate of loss of heterozygosity (LOH) through mitotic recombination. By utilizing this characteristic of Blm deficiency, we established an efficient method to introduce homozygous mutations into mESCs, which can be used for phenotype-driven recessive screen. It is generally thought that mitotic recombination is initiated by double-strand break. DNA repair machinery, however, possesses mechanisms that suppress deleterious crossovers between homologous chromosomes. Bloom helicase plays a central role to suppress such crossover; hence its deficiency causes elevated frequency of mitotic recombination. To directly answer if DSB can initiate mitotic recombination, we established a reporter cell line, in which the recognition site of I-SceI endonuclease was introduced in the Aprt gene in Blm-deficient mESCs. We used two types of I-SceI expression vectors; one expresses a mammalian codon-optimized I-SceI (ISceIo) and the other expresses I-SceIo fused with N-terminal 110-amino acids of Geminin (Gemi). Geminin-fused I-SceI can be stabilized only in lateS/G2 phase. After I-SceI transfection and subsequent selection, we isolated Aprt-deficient mutants. Half of the mutants showed LOH in the whole telomeric region from I-SceI site, but the other half showed local LOH near the I-SceI site. Further analyses suggested that large deletion was introduced and caused LOH, which was not seen in spontaneous LOH. We designed CGH probes in 300-bp resolution in 8Mb telomeric region of chr 8 (The Aprt gene locates 7Mb from the telomere) to map the deleted regions in these mutants.
2012-11-30 | E-MTAB-1116 | biostudies-arrayexpress
Project description:We have employed a laser capture microdissection technique and single nucleotide polymorphism arrays to characterize genomic alterations associated with the development of glioblastomas. Combined analysis of LOH and copy number revealed that more than half of the identified 254 LOH loci showed no copy number alteration, indicating the presence of copy-number neutral LOH Keywords: DNA copy number, Loss of heterozygosity Affymetrix 50K SNP mapping arrays were used to profile 14 primary glioblastomas (GBMs) with matched blood DNA samples. Loss of heterozygosity (LOH) and copy number abnormality (CNA) profiles were derived from each tumour-blood pair.
2009-03-01 | E-GEOD-10922 | biostudies-arrayexpress
Project description:We saw a patient who presented with respiratory distress from birth due to interstitial lung disease. Before the age of three months a diagnosis of nephrotic syndrome was made. Lung biopsy revealed pulmonary interstitial glycogenosis. Despite extensive investigations, no known genetic or infectious cause was found for the congenital nephrotic syndrome. The patient died at the age of 8 months due to respiratory failure. A 20 Mb homozygous region was identified on chromosome 17 in the patientM-bM-^@M-^Ys DNA, revealing a novel homozygous missense variant in ITGA3 gene. Genomic DNA was obtained from peripheral blood samples of the patient with interstitial lung fibrosis and nephrotic syndrome. Copy number variation (CNV) screening by means of microarray analyses was carried out on the Affymetrix GeneChip 250k (NspI) SNP array platform (Affymetrix, Inc., Santa Clara, CA, USA), which contains 25-mer oligonucleotides representing a total of 262,264 SNPs. Hybridizations were performed according to the manufacturerM-bM-^@M-^Ys protocols. Copy numbers and M-bM-^@M-^\long contiguous stretches of homozygosityM-bM-^@M-^] (LCSH/LOH) were determined using the 2.0 version of the CNAG (Copy Number Analyzer for Affymetrix GeneChip mapping) software package (Nannya Y, Sanada M, et al (2005) "A robust algorithm for copy number detection using high-density oligonucleotide single nucleotide polymorphism genotyping arrays." Cancer Res; 65: 6071M-bM-^@M-^S6079.). The average resolution of this array platform, described by McMullan et al is 150M-bM-^@M-^S200 kb (Mc McMullan DJ, Bonin M et al. (2009), M-bM-^@M-^\Molecular karyotyping of patients with unexplained mental retardation by SNP arrays: a multicenter studyM-bM-^@M-^] Hum Mutat. Jul;30(7):1082-92).
2012-08-28 | E-GEOD-40405 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE22544: Integration of transcript expression, copy number and LOH analysis of infiltrating ductal carcinoma of the breast: expression analysis GSE22839: Integration of transcript expression, copy number and LOH analysis of infiltrating ductal carcinoma of the breast: copy number analysis Refer to individual Series
2010-07-16 | E-GEOD-22840 | biostudies-arrayexpress